Have you sold your current home? If you have already sold your home, the plants in the ground must stay there unless you have an agreement with the purchaser (or can make one now in writing). If you can move stuff without a problem, I'd say start digging now and pot everything up in large pots to take with you. I'd chance it and plant in July, since you are in Ontario - I think with extra water you should do fine. I can't do that here in sweltering heat and the drieness we have, but I've done it plenty of times in Ontario in the middle of summer!

Hi Brodie, I'm Ontario too. Welcome to cottage gardening. I personally think that if you don't do anything significant to the yard, you can still move your plants. I have done this before too. (Hi GGG)

I would start out by digging out those plants now and for as long as you take a huge root ball, you won't have issues with your roses. As for you climbing hydrangeas, I suggest trimming the branches down to a manageable size and take a root ball. (I've done this before). As for the oakleaf hydrangea, it's not going to do well as a cutting. Dig it out. Same with the peonies since it hasn't come up yet. Don't expect it to bloom. Dig out the clematis now before it grows larger.

HINT, water well a day before digging out and don't fertilize them until the following year.

Good luck! I think you've already gotten better advice that I could give you.

It will be work, but I think having your plants from the old house would be very comforting.
kay

I'd say only take those things with you that you can't easily find again. Set aside a generous fund for the new garden and let it develop it's own character. Does your new house have some existing garden that you will be building on/have to take into account? There wasn't much here - or at least not that survived the renovation and addition to the house. But there were middle-aged white pines, a young red oak and a mature gree ash and they set the scene for a completely different backyard garden.

When we moved here in 1998, we only brought a few things and they are now my least favorite things in the garden. Starting over may sound like a setback or an undesirable thing but it usually isn't. It's an opportunity to be creative and not locked into the decisions you made years ago. I read something once that stuck in my mind - the garden you build in middle age is likely to be much better than the one you built in your youth. That is very true in my case I think. The garden here is much better than the one we left. I don't regret starting over at all.

Well, yes, you've had good advice. I would take whatever I could, and start potting it up now. Since the old home will become a building site, not much is going to survive. I would double check with the builder/new owner, and what ever I couldn't, or didn't what to take, I would offer to your local hort. society. Not only will that give you good karma (lol), it might bring some great trades. I don't think there is a good or a bad time to move - OK, in January in Montreal - yeah, not good. That is 'moving day', yeah? If you have access to your new property already, I'd find a part-shade corner where I could start squirrelling things away. And pay heed to Ianna's last line!!!

Nancy.

I was on the opposite side of this kind of dilemma several years ago when we sold our house. The lady who was buying it wanted to go ahead and move all her plants before it got too hot. It wasn't unusual for me to get home from work to find her in the yard with a grubbing hoe and a wagon load of plants.
If you have a good relationship with the sellers of the new place, moving some things now might be an option.